Terminal seal for ignition coils



y 1944- H. 1.. HARTZELL 2,348,254

TERMINAL SEAL FOR IGNITION COILS Filed Nov. 5, 1941 Patented May 9, 1944 TERMINAL SEAL FOR IGNITION COILS Herman L. Hartzell, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application November 5, 1941, Serial No. 417,959

Claims.

This invention relates to oil insulated ignition coils and more particularly to the construction of the subassembly which closes one end of the ignition coil housing and supports the high."

tension terminal. It is an object of the present invention to secure a leak proof construction of this sub-assembly. I have found that the seepage of oil is effectively blocked off where metal is in contact with an oil resisting rubber substitute such as neoprene. In accomplishing the object of the present invention I provideior the contact between metal and neoprene in the construction of my "improved high tension terminal support and coil housing and cover.

Further objects and advantages of the present invention will be apparent from the following description. reference being had to the accompanying drawing wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. l is a plan view of an ignition coil constructed in accordance with the present invention.

Fig. 2 is a sectional view of line 2-2 in Fig. 1.

Fig. 3 is a bottom View.

Figs. 4 and 5 are sectional views taken respectively on lines 4-4 and 5-5 of Fig. 2.

Referring to the drawing the ignition coil comprises a metallic tubular housing closed at its upper end by a cover assembly 2| and its lower end by cover sub-assembly 22, the construction of the latter being the subject of this application. The housing contains a central magnetizable core 23 supported by insulators 24 and 25 and surrounded by a secondary winding 26 and. a primary winding 21, the terminals 28 and 29 of winding 21 being connected with terminals 30 and 3|, respectively, insulatingly supported by cover 2|. The shank of terminal 30 is embedded in a Bakelite washer 32 and passes through a neoprene washer 33 in contact with the metal part 34 of the cover subassembly. An insulating washer 35 bears against the underside of cover member 34; a metal washer 36 bears against the washer 35; and the lower end of the terminal 38 is rivetted at 31 against washer 36. Terminal 3| is insulatingly supported by cover member 2| in a similar manner. The low potential end of secondary coil 26 is connected with terminal 30 and the high potential end is connected with the core 23. A tubular magnetizable body 39 is located between the housing 20 and the primary winding 21.

The lower end cover sub-assembly 22 comprises a metal ring 40 having a flange 4| formed around a flange at the lower end of the tubular housing 20 and having a flange 42 in contact with a gasket 43, of neoprene or other material resisting the creepage of oil which is clamped between porcelain insulators 44 and having annularly corrugated surfaces 44a and 45a, respectively, which bite into the gasket 43 and increase the electrical insulation between the central and peripheral portions of the assembly 22. The members 43, 44 and 45 are centrally apertured to receive a tubular high tension terminal 46 having a shoulder at 41 bearing against a metallic spring washer 48 and having its inner end rivetted at 49 against a metallic spring washer 50. Thus the porcelain insulators 44 and 45 are clamped with spring pressure against the gasket 43. This forms an oil tight seal between members 45, 44 and 43 and causes member 43 to be compressed so that it bears snugly against the metal ring 40 and against the terminal 46.

Terminal 46 receives a spring SI for making an electrical connection with the core 23. The upper end of spring 5| is locked within a nonconducting C-washer 52, the notch 53 of which provides for the passage of oil, introduced through the tubular high tension terminal 48.

After the coil has been filled with oil, the terminal 46 is closed by a metal peg 54 which is soldered at 55. Escape of oil through the lower end sub-assembly 22 is effectively blocked by the neoprene gasket 43 which is in contact with the high tension terminal 46 and with the metal ring 40'. No oil can leak around the outside of terminal 46 and the inside of ring 40.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. In an ignition coil having a case for enclosing a core, electric windings and an insulating liquid, means for closing the case and maintaining a seal thereof, said means comprising a metal ring attached to the case, centrally apertured insulating blocks one on each side of the ring and between which a portion of the ring is located, a centrally apertured gasket of material resisting the creepage of liquid located between the blocks and in contact with that portion of the ring located between the blocks, a metal rivet, the head of which provides the high tension terminal, and the shank of which extends through the central apertures in the insulating blocks and gasket and is rivetted over to clamp the blocks against the gasket and to cause the gasket to be pressed against the shank of the rivet and against the metal ring, and means electrically connecting the rivet and the core.

2. In an ignition coil according to. claim 1 wherein the closure member includes also two metallic spring washers through which the rivet extends, one washer being located between the head of the rivet and one insulating block and the other between the upset end of the rivet and the other insulating block in order to provide resilient clamping pressure.

3. In an ignition coil according to claim 1 wherein the surfaces of the insulating blocks facing the gasket are provided with concentric circular ridges which bite into the gasket and increase the liquid creepage distance.

4. In an ignition coil having a case for enclosing a core, electric windings and an insulating liquid, means for closing the case and maintaining a seal thereof, said means comprising a metal ring attached to the case, centrally apertured porcelain insulating blocks adjacent faces of which are provided with annular corrugations, a portion of the ring being located between the blocks, a central'apertured neoprene gasket located between the corrugated faces of the blocks and in contact with the ring, two resilient washers, one located against an insulating block, a tubular metal rivet, the head of which provides the high tension terminal, and the shank of which the case, and completes a seal extends through the central apertures in the insulating blocks and gasket and resilient washers and is rivetted over to clamp the blocks against the gasket and to cause the gasket to be pressed against the shank of the rivet and against the metal ring, the hole through the rivet providing for the passage of liquid into the coil case, 7

a plug closing the passage in the rivet, and means electrically connecting the rivet and the core.

5. In an ignition coil having a case for inclosing a core, electric windings and an insulating liquid, means for closing the case and maintaining a seal thereof, said means including a metallic ring attached to the case and having a tubular portion extendin into the case and an internal flange constituting a rest for a body of resilient non-porous insulating material; insulating blocks disposed on opposite sides of the flange and on opposite faces of the body and having arcuate ridges for engagement with the body; a terminal extending through the blocks and body; and means including a portion of the terminal for clamping the internal flange of the ring and the body between the blocks and compressing the body causing same to flow in directions to flll completely the spaces between the body and terminal, the blocks, and the tubular portion of said under surface of the flange respectively thereby effectingcomplete insulation of the terminal from against fluid creepage past said body.

' HERMAN L. HARTZELL. 

